Silicon carbide (SiC) substrates can be used to manufacture semiconductor devices. Specifically, a semiconductor device, such as a diode or transistor, can be manufactured, for example, by forming, by epitaxial growth on a silicon carbide substrate, a semiconductor layer composed of silicon carbide, and further forming electrodes and the like on the semiconductor layer.
The quality of a semiconductor layer formed by epitaxial growth on a silicon carbide substrate is greatly influenced by the surface roughness of a main surface of the silicon carbide substrate on which the semiconductor layer is formed. Accordingly, polishing, such as mechanical polishing (MP) or chemical mechanical polishing (CMP), is performed on a main surface of a silicon carbide substrate on which a semiconductor layer is to be formed by epitaxial growth. This ensures the smoothness of the main surface on which a semiconductor layer is to be formed, and a high-quality semiconductor layer can be epitaxially grown. Furthermore, regarding polishing of silicon carbide substrates, various studies have been conducted for the purpose of ensuring the smoothness of main surfaces (for example, refer to PTL 1 and PTL 2).